Link to caller URL

link_to “Back”, :back

Link to same URL with different format

Use params.merge as options. Ex.

<%= link_to "RSS feed", params.merge(:format => :rss), :class => "feed_link" %>

link_to some url with current params

Code example

link_to "some text", users_path(:params => params, :more_params => "more params")

Opening a link in a new window

Use “_blank”, not “_new” to open a link in a new window.

link_to "External link", "http://foo.bar", :target => "_blank"
# => <a href="http://foo.bar" target="_blank">External link</a>

Anchor tag in link_to

Code example

link_to("some text", articles_path(:anchor => "comment"))

will output <a href = “/articles#comment” >some text

Window open a dialog of no menu, no status, have scroll

Example

link_to name, url, :popup => ['dialog name','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes']

HTML5 data- attributes using RESTful approach

HTML5 specifies extensible attributes like data-foo=“bar” (or as in Twitter Bootstrap data-toggle=“modal”), which poses two problems for Rails.

First, if you’re using symbol notation in link_to to specify attributes, this fails (dash is not a valid symbol character), so

Invalid!

link_to "Edit", @user, :class => "btn", :data-toggle => "modal"

There are two solutions:

1. put the symbols in quotes,

2. use the special :data hash

Solution 1: Quote Symbols

link_to "Edit", @user, :class => "btn", "data-toggle" => "modal"

Solution 2: Use the :data hash

link_to "Edit", @user, :class => "btn", :data => {:toggle => "modal"}

Resulting HTML

<a href="/users/1" class="btn", data-toggle="modal">Edit</a>

The second is minimally documented, but as a hash, can accept multiple values and is perhaps a little cleaner

link_to with block (Edge Rails)

New ability in Edge Rails to use link_to called with a block, e.g. The following is a view example:

<% link_to some_path do %>
  <strong>Awesome link</strong> -- it's pretty awesome
<% end %>

This change was made in: http://github.com/rails/rails/commit/8190bce8bc7249b7b9f3680195336eb3ca9508ee

Patch in yourself, or likewise you can use the following snippet (which is the new link_to method with modifications [there are also Array extensions on edge to provide .second, .third etc which aren’t present]).

url_helper_extensions.rb

module ActionView
  module Helpers
    module UrlHelper
      def link_to(*args, &block)
        if block_given?
          options = args.first || {}
          html_options = args[1]
          concat(link_to(capture(&block), options, html_options))
        else
          name = args.first
          options = args[1] || {}
          html_options = args[2]

          url = case options
            when String
              options
            when :back
              @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()'
            else
              self.url_for(options)
            end

          if html_options
            html_options = html_options.stringify_keys
            href = html_options['href']
            convert_options_to_javascript!(html_options, url)
            tag_options = tag_options(html_options)
          else
            tag_options = nil
          end

          href_attr = "href=\"#{url}\"" unless href
          "<a #{href_attr}#{tag_options}>#{name || url}</a>"
        end
      end
    end
  end
end

:confirm, :popup, and :method override :onclick

upplying any combination of :confirm, :popup, and/or :method options to the link_to method results the :onclick option being overridden.

Example:

link_to "Delete", '#', :confirm=>"Are you sure?", :onclick=>"destroyJsFunction()"
# expected output
# => <a href="#" onclick="if(confirm('Are you sure?')) {destroyJsFunction()}; return false;">Delete</a>
# actual output
# => <a href="#" onclick="return confirm('Are you sure?');">Delete</a>

Note that the actual output doesn’t include any mention of the “destroyJsFunction()” passed to the link_to method.

Rails 3 will use unobtrusive JavaScript, and I haven’t tested how that will interact with the :onclick option.

Remember to sanitize name

While useful when in need of richer markup inside a link, the name parameter isn’t sanitized or escaped and thus should be escaped when its content can’t be guaranteed to be safe.

E.g.

link_to(url, url)

may cause problems with character entities if url contains ampersands.

Correct usage

link_to(h(url), url)

This applies to all dynamic content.

Expression

You can put some expression too. For example for I18n (using haml on view):

# some_locale.yml

links:
  contacts: "My contacts"

# index.html.haml

= link_to "#{t "links.contacts"}", :action => 'contacts'

Text and Image together in #link_to

Code Example

link_to “Hello World #{ image_tag(‘web/worl.png’) }”.html_safe, some_path

:method => :delete, etc.

If you’re upgrading to Rails 3 you’ll need to make sure you include rails.js (which is in public/javascripts when you rails new someproject) You’ll need to include it after prototype. And you’ll need to have a 1.7 version of prototype.

When you do a

link_to "Delete", @some_obj, :method => "delete", :confirm => "Are you sure?"

Rails 3 will generate

<a href="some_obj/id" data-confirm="Are you sure?" data-method="delete">Delete</a>

rails.js will creates observers that convert that into a form.

Be aware that this probably won’t work as a link from inside a form (since forms in forms isn’t valid).

link_to with :as routing

The following will not work when your post model is routed with the :as option:

link_to("View post", @post)

Instead, use the helper with your custom name:

link_to("View post", :url => renamedpost_path(@post))

logic in class/id

If you need to place some simple logic in class or like that, I think that best to make it with simple brackets:

Code example

<%= link_to ‘All actions’, switch_action_tab_path, :remote => true, :class => (‘selected’ if @tab == ‘all’) %>

Using fontawesome icons inside link_to

<%= link_to (‘<i class=“fa fa-thumbs-up fa-lg”> </i>’).html_safe, vote_path(@image)%>

in this way you can use thumbs-up icon instead of usual text such as “like” in link_to

Link with relative url

By default link_to opens url as absolute if path does not contain http:// or https:// For Ex.

link_to ‘View’, “test123.abc.com/ag/acf”, target: :_blank, title: “Click to open url in a new tab”

Then it’ll open the link with absolute path not only with test123.abc.com/ag/acf.

If link_to path contains http:// then it takes the relative url.

link_to ‘View’, “http://test123.abc.com/ag/acf”, target: :_blank, title: “Click to open url in a new tab”

Now it open the relative url as it contains.

:popup gotcha in IE

If your popup title contains spaces or escaped HTML characters, Internet Explorer (at least 6/7) will not pop up a new window but open the link in the existing browser window.